Maria Emma Mejia, the Colombian-born secretary general of the Union of South American Nations and a veteran of her country’s valiant struggle against the cartels in the 1980s, told me recently, “After 40 years of the war against drugs, there’s a new approach.”

It’s still nascent, with neither coherent message nor unifying leadership — but several regional leaders, including Colombian President Juan Manuel Santos, have started talking openly about the decriminalization or even full legalization of narcotics.

Guatemala’s new president, Otto Perez Molina, a former general who’s had his fill of the war against drug lords, is the boldest of the new converts. By decriminalizing the narco trade, “you would get rid of money laundering, smuggling, arms trafficking and corruption,” he said last month.

Though out-of-office leaders have long made such arguments, Molina is the first US-friendly head of state to openly challenge the premise of the war on drugs.

Staggering profits fuel Latin America’s black-market drug economies, making a mockery of the law enforcers’ Sisyphean attempts to fight the traffickers. And the rot goes far beyond crime.

Venezuela for years nurtured the FARC narco-gang in its war against the US-allied Colombian government — and Venezuelan generals got rich in the process. Now, as the American Enterprise Institute’s Roger Noriega wrote in Foreign Policy this week, those Venezuelan generals, still tied to the traffickers, are scrambling for position in the battle to take over as caudilloHugo Chavez succumbs to cancer.

Noriega, with better sources on Venezuela than any other expert writing for the public, predicts chaos as the generals fight, and as Iran and other US enemies solidify their foothold in a vital Latin American nation.

Meanwhile, as Mexico’s Felipe Calderon winds down his presidency, his PAN party seems set to losing power to its rival, the PRI, in the July 1 election. Why? The drug war Calderon launched after assuming power in 2006 has made life in large swaths of the country unbearable — not to mention some 50,000 dead.

We endlessly debate the morality of our Iraq and Afghanistan wars. Yet nobody argues over the virtue of the war on drugs, fought on our behalf and partly at our expense — we spend nearly $500 million a year on it outside our borders.

Instead, Vice President Joe Biden went to several Central American capitals last month to shush the “new paradigm” talk. Yes, he paternalistically told the long-suffering locals, new ideas are “worth discussing.” But, no, we won’t take them seriously.

As Dan Restrepo, the White House director for the Western Hemisphere, told reporters Wednesday, “It’s a debate that we welcome having, because it helps demystify this as an option” — but Obama “doesn’t support decriminalization.”

Neither does any other presidential candidate this side of Ron Paul.

So we’ll likely wage more battles in a war that to date has undermined the rule of law near our borders, enriched the region’s most ruthless sociopaths and handed openings to our worst enemies. On to victory.

But does anyone really know what “victory” in the war on drugs looks like?